A review of Wednesday's men's singles action at the Australian Open.

Novak Djokovic continued his smooth progress through the top half of the draw at the Australian Open with a crushing win over Ryan Harrison.

Djokovic, looking to become the first man in the Open era to win three successive Melbourne titles, showed no mercy to his young American opponent with a ruthless display on Rod Laver Arena to extend his run of successive wins here to 16.

Harrison was brushed aside 6-1 6-2 6-3 in just 90 minutes as the world number one marched on to a third-round clash with Radek Stepanek.

"I tried to focus from the start," said Djokovic, "but he had nothing to lose and came out and hit some big serves.

"I managed to get some important breaks at the start of the match and then I was a set up after 20 minutes and had the mental advantage.

"It is a pity for him - I don't think he played at his best, probably because of the occasion playing on centre court, but I wish him the best - he has a good future."

David Ferrer was made to work harder than expected but still progressed.

The fourth seed was predicted to have few problems with American Tim Smyczek, who only earned a place in the main draw following compatriot John Isner's withdrawal through injury, but was instead pushed to four sets.

Spaniard Ferrer eventually came through 6-0 7-5 4-6 6-3 to set up a clash with Cypriot Marcos Baghdatis, himself a four-set winner over Japan's Tatsuma Ito.

Fifth seed Tomas Berdych and 10th seed Nicolas Almagro had a far easier time of it.

American Sam Querrey moved through but not in the way he would have wanted after more terrible misfortune for Brian Baker.

Baker led the 20th seed 7-6 (7/2) 1-1 when he trapped his right knee mid-rally and was taken off the court in a wheelchair. His management group later confirmed he had torn his lateral meniscus and would be out for up to four months.

It is the latest blow for the 27-year-old, who battled his way into the top 100 last year after six years out with a collection of injuries.

Querrey said: "He's the last person that deserves anything like that with his five or six surgeries already.

"He does everything right, treats his body great trying to come back and then something like that happens. It's just so unlucky."

Querrey will meet Stanislas Wawrinka in round three while Kevin Anderson will take on Fernando Verdasco after their wins against Andrey Kuznetsov and Xavier Malisse respectively. Kei Nishikori will play Evgeny Donskoy, who beat Russian countryman and 23rd seed Mikhail Youzhny in five sets.

Eighth seed Janko Tipsarevic squandered a two-set lead but hit back to see off Slovakian Lukas Lacko 6-3 6-4 3-6 4-6 7-5.